My friend's GTI MK6 with K04 is having that same problem as yours with his HFS4v3.1 that it comes in way late at 4000rpm when the TRSH is set to 10 o'clock (which is about 27% FIDC). And when the WMI finally triggers; it immediately flashed to max acting just like an on-off switch. This is when trigger is set to FIDC.

The reason I asked is, I want to know if K04 GTI mapping really gets to 27% FIDC at around 4,000rpm. I don't think it is, but I cannot confirm it.

I too had the same issue and my car is Golf MK6 TSI 160, twincharger model. But is now solved by switching the wiring on the injector. At least on mine, there is another hint that is during FDC test the Aquamist flow gauge can only display 4 bars when it should be displaying 8 bars.

So maybe you can try the FDC test and see how many bars Aquamist flow gauge displays. But if it did displays 8 bars, I would just try reversing the wiring on the injector and see if that solves your issue.

Also, on HFS3 there should be a link you can drop a blob of solder at the back of the circuit board to activate flow based on 30% boost / 70% FIDC. You can find the exact spot on the instruction manual.

My friend's GTI MK6 with K04 is having that same problem as yours with his HFS4v3.1 that it comes in way late at 4000rpm when the TRSH is set to 10 o'clock (which is about 27% FIDC). And when the WMI finally triggers; it immediately flashed to max acting just like an on-off switch. This is when trigger is set to FIDC.

The reason I asked is, I want to know if K04 GTI mapping really gets to 27% FIDC at around 4,000rpm. I don't think it is, but I cannot confirm it.

I too had the same issue and my car is Golf MK6 TSI 160, twincharger model. But is now solved by switching the wiring on the injector. At least on mine, there is another hint that is during FDC test the Aquamist flow gauge can only display 4 bars when it should be displaying 8 bars.

So maybe you can try the FDC test and see how many bars Aquamist flow gauge displays. But if it did displays 8 bars, I would just try reversing the wiring on the injector and see if that solves your issue.

Also, on HFS3 there should be a link you can drop a blob of solder at the back of the circuit board to activate flow based on 30% boost / 70% FIDC. You can find the exact spot on the instruction manual.

Yes, She is K04.

I need to fomd that location on the FS3 board and check that minei is set for 30% boost.
Currently it feels like it completely ignores boost.

Btw, something to add. Although this is a GTI almost everything that can make it an S3 has been done.
So S3 injectors, S3 boost pressure Censor, K04 Turbo etc.

So tonight I found I can get it to kick in under lower revs just by adjusting the dial right back.... but it still doesnít kick in under boost load.

I then changed across to an MPS based trigger and that works perfectly.

So if I know MPS works and is reading the Censor. Why would the System not work under boost ?
Could it be the setting on the board for the different Map Censor ranges ? But then why would it work under MPS ?

Iíll try fiddle a little more today.

Another thing. Why would my hfs3 board be set to custom ?
What does that change ?